Cascade Grignard Addition: Propargyl Claisen Rearrangement for the Stereoselective Synthesis of α-Allene Quaternary Centers in Cyclohexanones.

ABSTRACT: We report a new method for the enantio- and diastereoselective synthesis of α-allene quaternary centers in fully substituted cyclohexanones at the α-positions. This reaction involves asymmetric 1,2-carbonyl addition to 2-O-propargyl enones using a mixture of Grignard reagents and the PMP-H8-BINOL ligand. The resulting magnesium alkoxide chelate intermediate then activated the propargyl vinyl ether moiety, thereby triggering a cascade propargyl Claisen rearrangement in a diastereoselective manner. The synthetic applications of this method in the context of complex molecules are also demonstrated.

SUBMITTER: Armendariz-Gonzalez E 

PROVIDER: S-EPMC12305655 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature